CREATE TABLE #TEST
(A VARCHAR(10) NULL,B VARCHAR(MAX) NULL)
INSERT INTO #TEST
SELECT ‘A‘,‘A001‘
UNION ALL
SELECT ‘A‘,‘A002‘
UNION ALL
SELECT ‘A‘,‘A003‘
UNION ALL
SELECT ‘B‘,‘B001‘
UNION ALL
SELECT ‘B‘,‘B002‘
SELECT * FROM #TEST
--先来看一个简单的，效果如下图所示：
SELECT STUFF((SELECT ‘,‘+B FROM #TEST FOR XML PATH(‘‘)),1,1,‘‘)
---------------------------------------------------------------
--再来个我们想要的，效果见下图：
SELECT DISTINCT t1.A,
REPLACE((SELECT B AS [data()] FROM #TEST t2 WHERE t1.A=t2.A FOR XML PATH(‘‘)),‘ ‘,‘,‘) AS B
FROM #TEST t1
---------------------------------------------------------------
利用FOR XML PATH行转列（根据某字段分组，多行数据转成一行，并用逗号隔开）
原文：https://www.cnblogs.com/lrl45/p/12001108.html